Pesticides and metals in goji berries from Ningxia
What it found
In tests of goji berries from plantations and supermarkets in China, levels of five pesticides were below limits, and the authors calculated that the amounts of pesticides and metals people would take in from eating them did not exceed safety thresholds.
What they found
Pesticide levels
Five pesticides were found in plantation samples, all below their maximum residue limits. Only dichlorvos was found in supermarket samples, and deltamethrin was not found in any sample.
Metal levels
Copper, zinc, arsenic, lead, nickel and cadmium were found in samples from both sources. Nickel and zinc levels were above the maximum residue limits for fruits, but the authors note these limits are not set for herbal medicines.
Non-cancer risk
The hazard quotient for each chemical and the hazard index for all chemicals combined were well below 1, which the authors say means no non-cancer effects are expected from eating these goji berries.
Cancer risk from arsenic
The calculated cancer risk from arsenic in the goji berries was far below the level considered negligible by the US Environmental Protection Agency.
Source comparison
Goji berries from plantations posed a slightly higher risk than those from supermarkets. Metals contributed more to the overall risk than pesticides.
Key factors
The factors that most affected the risk estimates were how often people ate goji berries and the arsenic content of the berries.
What the authors conclude
“The potentially harmful effects of the L. barbarum L. are more likely from berries obtained from plantations than those from supermarkets, and metal exposure is more dangerous than pesticide exposure.”
Also in their conclusions
- They conclude that no population would be exposed to hazardous chemicals exceeding existing standards from eating these goji berries.
- They advise that controlling the frequency of intake is the most important way to reduce the non-cancer risk, and controlling arsenic content is the most effective way to reduce the cancer risk.
- They note that further study is needed on how washing and drying remove pesticides and metals, and on how metal levels vary by region.
How it was done
Goji berries are widely used as a food and traditional medicine, but they can contain pesticide residues and metals. The authors wanted to measure these and assess the health risks for consumers.
They collected 37 goji berry samples from plantations in Zhongning County and 80 from supermarkets in Yinchuan, Ningxia, China. They measured six pesticides and six metals in the berries and surveyed 558 people about how much goji they ate to estimate daily exposure and health risks.
What it can’t tell you
- This study measured chemical levels in goji berries from one region of China and estimated risks based on a survey of local people. The results may not apply to goji berries from other areas or to people with different eating habits.
- The risk estimates rely on assumptions about how much goji people eat and how long they are exposed. Actual risks for an individual could differ.
Who paid
- Funding
- Funded by National Natural Science Foundation of China; Ningxia Key Research and Development Program; Ministry of Education"ChunHui"plan (from the PubMed record).
- Conflicts
- The authors declare no competing interests.
- Authors work at
- Ningxia Medical University, China; Ningxia University, China
The paper
- Title
- Levels and health risk assessment of pesticides and metals in Lycium barbarum L. from different sources in Ningxia, China
- Type
- Study
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Zhang Y, Qin J, Wang Y, et al (2022). Levels and health risk assessment of pesticides and metals in Lycium barbarum L. from different sources in Ningxia, China. Scientific reports. doi:10.1038/s41598-021-04599-5Free full textPubMed 35022452DOI
Summary written 29 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error